function setVisibility( /* Layer */ objLayer, /* boolean */ visible )
{
	if(document.layers)
	{
		objLayer.visibility  = (visible == true) ? 'show' : 'hide';
	}
	else
	{
		objLayer.style.visibility =  (visible == true) ? 'visible' : 'hidden';
	}
}
function getLayerRef ( /* String */ id, /* optional HTML-Object */ document)
{
	if (!document)
	document = window.document;
	
	if (document.layers) 
	{
		for (var l = 0; l < document.layers.length; l++)
			if (document.layers['l'].id == id)
				return document.layers['l'];
		for (var l = 0; l < document.layers.length; l++) 
		{
			var result = getLayerRef(id, document.layers['l'].document);
			if (result)
				return result;
		}
		return null;
	}
	else if (document.all) 
	{
		return document.all['id'];
	}
	else if (document.getElementById) 
	{
		return document.getElementById(id);
	}
}